Heretofore, in general, Au alloys having an elevated Hv of 100 or more have been popularly used to produce accessories such as neck chains, brooches, rings, etc. Such Au alloys include, for example, K14 alloys and K18 alloys comprising pure gold having a purity of 99% or more and approximately from 25 to 40% by weight of alloying components such as Ag, Cu and even Ni, Pd, Zn, etc.
On the other hand, it is said ideal that the above-mentioned accessories are made of pure gold in view of their color and high-quality appearance. However, pure gold has Hv of about 32 as its ingot, while having Hv of about 80 as its worked wire. Even though such pure gold is worked to have an elevated hardness, the elevated hardness of the thus-worked pure gold is inevitably lowered not only with the lapse of time but also when heated by brazing or the like. For these reasons, pure gold accessories are always soft and are therefore easily scratched. It is extremely difficult to keep the esthetic value of such pure gold accessories for a long period of time, and the practical application of pure gold accessories is limited to only an extremely narrow range at present.